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changes to simulate examples

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shiffman
2011-12-15 17:27:25 +00:00
parent 2072bceb6e
commit 65f795f70d
12 changed files with 205 additions and 307 deletions
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java/examples/Topics/Simulate/Flocking/Boid.pde
+80 -98
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@@ -2,31 +2,36 @@
class Boid {
PVector loc;
PVector vel;
PVector acc;
PVector location;
PVector velocity;
PVector acceleration;
float r;
float maxforce; // Maximum steering force
float maxspeed; // Maximum speed
Boid(PVector l, float ms, float mf) {
acc = new PVector(0,0);
vel = new PVector(random(-1,1), random(-1,1));
loc = l.get();
Boid(float x, float y) {
acceleration = new PVector(0,0);
velocity = new PVector(random(-1,1),random(-1,1));
location = new PVector(x,y);
r = 2.0;
maxspeed = ms;
maxforce = mf;
maxspeed = 2;
maxforce = 0.03;
}
void run(ArrayList boids) {
void run(ArrayList<Boid> boids) {
flock(boids);
update();
borders();
render();
}
void applyForce(PVector force) {
// We could add mass here if we want A = F / M
acceleration.add(force);
}
// We accumulate a new acceleration each time based on three rules
void flock(ArrayList boids) {
void flock(ArrayList<Boid> boids) {
PVector sep = separate(boids); // Separation
PVector ali = align(boids); // Alignment
PVector coh = cohesion(boids); // Cohesion
@@ -35,60 +40,42 @@ class Boid {
ali.mult(1.0);
coh.mult(1.0);
// Add the force vectors to acceleration
acc.add(sep);
acc.add(ali);
acc.add(coh);
applyForce(sep);
applyForce(ali);
applyForce(coh);
}
// Method to update location
void update() {
// Update velocity
vel.add(acc);
velocity.add(acceleration);
// Limit speed
vel.limit(maxspeed);
loc.add(vel);
velocity.limit(maxspeed);
location.add(velocity);
// Reset accelertion to 0 each cycle
acc.mult(0);
acceleration.mult(0);
}
void seek(PVector target) {
acc.add(steer(target,false));
}
void arrive(PVector target) {
acc.add(steer(target,true));
}
// A method that calculates a steering vector towards a target
// Takes a second argument, if true, it slows down as it approaches the target
PVector steer(PVector target, boolean slowdown) {
PVector steer; // The steering vector
PVector desired = PVector.sub(target,loc); // A vector pointing from the location to the target
float d = desired.mag(); // Distance from the target is the magnitude of the vector
// If the distance is greater than 0, calc steering (otherwise return zero vector)
if (d > 0) {
// Normalize desired
desired.normalize();
// Two options for desired vector magnitude (1 -- based on distance, 2 -- maxspeed)
if ((slowdown) && (d < 100.0)) desired.mult(maxspeed*(d/100.0)); // This damping is somewhat arbitrary
else desired.mult(maxspeed);
// Steering = Desired minus Velocity
steer = PVector.sub(desired,vel);
steer.limit(maxforce); // Limit to maximum steering force
}
else {
steer = new PVector(0,0);
}
// A method that calculates and applies a steering force towards a target
// STEER = DESIRED MINUS VELOCITY
PVector seek(PVector target) {
PVector desired = PVector.sub(target,location); // A vector pointing from the location to the target
// Normalize desired and scale to maximum speed
desired.normalize();
desired.mult(maxspeed);
// Steering = Desired minus Velocity
PVector steer = PVector.sub(desired,velocity);
steer.limit(maxforce); // Limit to maximum steering force
return steer;
}
void render() {
// Draw a triangle rotated in the direction of velocity
float theta = vel.heading2D() + PI/2;
float theta = velocity.heading2D() + radians(90);
fill(200,100);
stroke(255);
pushMatrix();
translate(loc.x,loc.y);
translate(location.x,location.y);
rotate(theta);
beginShape(TRIANGLES);
vertex(0, -r*2);
@@ -100,26 +87,25 @@ class Boid {
// Wraparound
void borders() {
if (loc.x < -r) loc.x = width+r;
if (loc.y < -r) loc.y = height+r;
if (loc.x > width+r) loc.x = -r;
if (loc.y > height+r) loc.y = -r;
if (location.x < -r) location.x = width+r;
if (location.y < -r) location.y = height+r;
if (location.x > width+r) location.x = -r;
if (location.y > height+r) location.y = -r;
}
// Separation
// Method checks for nearby boids and steers away
PVector separate (ArrayList boids) {
float desiredseparation = 20.0;
PVector separate (ArrayList<Boid> boids) {
float desiredseparation = 25.0f;
PVector steer = new PVector(0,0,0);
int count = 0;
// For every boid in the system, check if it's too close
for (int i = 0 ; i < boids.size(); i++) {
Boid other = (Boid) boids.get(i);
float d = PVector.dist(loc,other.loc);
for (Boid other : boids) {
float d = PVector.dist(location,other.location);
// If the distance is greater than 0 and less than an arbitrary amount (0 when you are yourself)
if ((d > 0) && (d < desiredseparation)) {
// Calculate vector pointing away from neighbor
PVector diff = PVector.sub(loc,other.loc);
PVector diff = PVector.sub(location,other.location);
diff.normalize();
diff.div(d); // Weight by distance
steer.add(diff);
@@ -136,7 +122,7 @@ class Boid {
// Implement Reynolds: Steering = Desired - Velocity
steer.normalize();
steer.mult(maxspeed);
steer.sub(vel);
steer.sub(velocity);
steer.limit(maxforce);
}
return steer;
@@ -144,52 +130,48 @@ class Boid {
// Alignment
// For every nearby boid in the system, calculate the average velocity
PVector align (ArrayList boids) {
float neighbordist = 25.0;
PVector steer = new PVector(0,0,0);
PVector align (ArrayList<Boid> boids) {
float neighbordist = 50;
PVector sum = new PVector(0,0);
int count = 0;
for (int i = 0 ; i < boids.size(); i++) {
Boid other = (Boid) boids.get(i);
float d = PVector.dist(loc,other.loc);
for (Boid other : boids) {
float d = PVector.dist(location,other.location);
if ((d > 0) && (d < neighbordist)) {
steer.add(other.vel);
count++;
}
}
if (count > 0) {
steer.div((float)count);
}
// As long as the vector is greater than 0
if (steer.mag() > 0) {
// Implement Reynolds: Steering = Desired - Velocity
steer.normalize();
steer.mult(maxspeed);
steer.sub(vel);
steer.limit(maxforce);
}
return steer;
}
// Cohesion
// For the average location (i.e. center) of all nearby boids, calculate steering vector towards that location
PVector cohesion (ArrayList boids) {
float neighbordist = 25.0;
PVector sum = new PVector(0,0); // Start with empty vector to accumulate all locations
int count = 0;
for (int i = 0 ; i < boids.size(); i++) {
Boid other = (Boid) boids.get(i);
float d = loc.dist(other.loc);
if ((d > 0) && (d < neighbordist)) {
sum.add(other.loc); // Add location
sum.add(other.velocity);
count++;
}
}
if (count > 0) {
sum.div((float)count);
return steer(sum,false); // Steer towards the location
sum.normalize();
sum.mult(maxspeed);
PVector steer = PVector.sub(sum,velocity);
steer.limit(maxforce);
return steer;
} else {
return new PVector(0,0);
}
}
// Cohesion
// For the average location (i.e. center) of all nearby boids, calculate steering vector towards that location
PVector cohesion (ArrayList<Boid> boids) {
float neighbordist = 50;
PVector sum = new PVector(0,0); // Start with empty vector to accumulate all locations
int count = 0;
for (Boid other : boids) {
float d = PVector.dist(location,other.location);
if ((d > 0) && (d < neighbordist)) {
sum.add(other.location); // Add location
count++;
}
}
if (count > 0) {
sum.div(count);
return seek(sum); // Steer towards the location
} else {
return new PVector(0,0);
}
return sum;
}
}